Delweng

> What would be the use case for this tracer? We want to get all contracts/accounts' state change before and after a TX execution. It is useful for analyzing some...

So we can extract the difference of the state, eg: https://etherscan.io/tx/0x9ef7a35012286fef17da12624aa124ebc785d9e7621e1fd538550d1209eb9f7d#statechange 

> Nitpick: please rename to `stateDiffTracer` > > Edit: also it was on my backlog to implement this tracer myself, thanks for opening the PR! I happen to need to...

> Thanks for the PR - we just discussed it in triage - and in general this is something that would be nice to have. Just the implementation needs some...

@ligi add a simple testcase inside [eth/tracers/internal/tracetest](eth/tracers/internal/tracetest] BTW, seems the `4byte`, `prestate` and other tracers doesn't have testcases. If necessary, I will file another PR

@s1na PTAL, merge the `statediff` into `prestate` with config as `collectPost: true`

You need to decrease the request concurrency

This problem occurred after the [v0.7.0](https://github.com/crypto-org-chain/cronos/releases/tag/v0.7.0) upgrade

@xiang90 we occured the same issue, how could you fixed it?

@gehel Thanks for your advise, I'll consider for a PR later.